High‐performance thermoplastic elastomers/carbon nanotubes nanocomposites: Mechanical behavior, rheology, and durability

Abstract

Advanced polystyrene‐b‐polybutadiene‐b‐polystyrene (SBS) based nanocomposites containing bare carbon nanotubes (CNTs) and CNTs bearing hydroxyl functional groups (CNTs‐OH) have been formulated and fully characterized. In particular, the reinforcement effect of CNTs and CNTs‐OH on SBS was deeply investigated through mechanical and dynamical thermo‐mechanical analysis and the rheological response of SBS‐based nanocomposites was investigated and discussed. The mechanical properties of SBS/CNTs and even more of SBS/CNTs‐OH nanocomposites are substantially superior to those of neat SBS, due to the uniformly dispersed nanofillers throughout the polymeric matrix. The presence of ‐OH groups onto CNTs promotes the stress transfer from polymer to CNTs, strengthening the overall performance of the nanocomposite. Moreover, the durability of SBS‐based nanocomposites was monitored through mechanical, dynamic mechanical, and rheological analysis. SBS‐based nanocomposites showed a significant improved photo‐stability with respect to the neat matrix, due to the presence of CNTs that are able to stabilize efficiently SBS because of their acceptor‐like electron properties. The presence of ‐OH groups onto CNTs enhance the protection ability of CNTs due to the larger amount of surface defects, that improves their radical scavenging activity. Furthermore, CNTs‐OH can act as chain‐breaking electron donor, becoming responsible for radical termination during SBS degradation. POLYM. COMPOS., 38:E381–E391, 2017. © 2015 Society of Plastics Engineers